Legal Question in Business Law in California

I don't know the full details of your plans to operate, so you may be either a sublessee or a licensee. But that distinction does not relieve you of your obligation to have a business license or to carry worker's compensation insurance. If you employ anyone other than yourself, you had better carry worker's compensation insurance.

Assuming that you are already the operator of the bakery, the answer depends on the definition of allowed use in your existing lease and the definition of your operations in the existing business license, since selling breakfasts is not all that different then selling bakery items. If these definitions are broad enough, it may be that you do not need a sublease nor a new business license. If you are not the operator of the bakery, however, then the preceding attorney's response is accurate.